Direct aligned bonding is done at high temperature, which makes the bond very strong (high-pressure resistant up to 150 bar / 2175 psi for certain structures).
In the basic chip manufacturing process, a glass layer with holes is bonded to another glass layer with channels. For more complex devices, multi-stack bonding is required. Micronit has in-house capabilities to bond multiple wafers. This is also suitable when a large internal volume is required. Devices can then be stacked in order to raise the internal volume.
Micronit is one of the few companies in microtechnology that offers direct glass to glass and glass to silicon bonding (without an intermediate layer).